Jef,

OpenGL should be already installed with the video driver, Direct X with Windows operating system.

In Meta, press D3D or GL button in the left View menu bar to enable rendering.
Press the Fc button in the left Edit Option menu bar to enable select faces.
The Fc button in the top panel should be pressed to show faces.
Be sure, the object is not locked in the right Object Panel (the key symbol in front of the names).

Regards
Rodeo